For digital cameras, a technology in which an autofocus (AF) operation using a contrast method (also referred to as a “contrast AF” operation) based on an image signal acquired from an image pickup device is performed has been developed. For example, Japanese Unexamined Patent Application Publication No. 2006-227080 describes a technology in which a face region of a subject in an image to be captured is identified, and a contrast AF operation is performed on the basis of an image signal from a ranging area including the face region.
In contrast, in recent years, digital single-lens reflex cameras (DSLRs) have been widely used. The DSLRs employ an AF method using a phase difference detection method (hereinafter also referred to as a “phase difference AF”).
In the phase difference AF, a focus position of a focus lens is computed using subject's light in a ranging area set within a field of view, that is, in an imaging area.
However, the ranging area for phase difference AF is fixedly set in a predetermined area in the imaging area. Accordingly, in a composition determined by a photographer (also referred to as a “user”), if a main subject is not included in the ranging area, an appropriate image to be captured in which the main subject is in focus, as described in Japanese Unexamined Patent Application Publication No. 2006-227080, may not be obtained.
In addition, such a problem may occur in not only digital single-lens reflex cameras but also in all digital cameras that employ phase difference AF as an AF method.
Accordingly, it is an object of the present invention to provide an image pickup apparatus that can decrease the probability of an image in which a main subject is not in focus being captured.